_An improvement of the fortieth Experiment_.

And, _Pyrophilus_, to confirm yet further the Notions that led me to think
on the propos'd Experiment, I shall acquaint you with another, which when I
had conveniency I have sometimes added to it, and which has to the
Spectators appear'd little less Odd than the first; And though because the
Liquor, requisite to make the Trial succeed well, must be on purpose
prepar'd anew a while before, because it will not long retain its fitness
for this work, I do but seldome annex this Experiment to the other, yet I
shall tell you how I devis'd it, and how I make it. If you boyl Crude
Antimony in a strong and clear _Lixivium_, you shall separate a Substance
from it, which some Modern _Chymists_ are pleas'd to call its Sulphur, but
how deservedly I shall not here examine, having elsewhere done it in an
Opportune place; wherefore I shall now but need to take notice, that when
this suppos'd Sulphur (not now to call it rather a kind of _Crocus_) is let
fall by the Liquor upon its Refrigeration, it often settles in Flakes, or
such like parcels of a Yellow Substance, (which being by the precedent
dissolution reduc'd into Minute parts, may peradventure be made to take
Fire much more easily than the Grosser Powder of unprepar'd Antimony would
have done.) Considering therefore, that common Sulphur boyl'd in a
_Lixivium_ may be Precipitated out of it by Rhenish-wine or White-wine,
which are Sowrish Liquors, and have in them, as I elsewhere shew, an Acid
Salt; and having found also by Trial, that with other Acid Liquors I could
Precipitate out of Lixiviate Solvents some other Mineral concretions
abounding with Sulphureous parts, of which sort is crude Antimony, I
concluded it to be easie to Precipitate the Antimony dissolv'd, as was
lately mention'd, with the Acid Oyl of Vitriol; and though common Sulphur
yields a White Precipitate, which the _Chymists_ call _Lac Sulphuris_, yet
I suppos'd the Precipitated Antimony would be of a deep Yellow Colour, as